Digi7ech

iTrader: (1)

OK on my rebuild the voltage wheil running at 1k is LOW.

It's around 11.9Volts.

Now I swapped what I believe is a good alt.
This one isn't helping.

I doubt I have 2 bad alternators. I will take them to a place to get tested tomorrow.

How can I test for problems in my main harness(ring terminal)?

Currently I am running the car with the back plug out.
It's NA so the plug goes to the EFI harness.

This shouldn't affect the charging system right?Since it's just supposed to be a warning light right?
Whic leads to both of those wires on the plug should have voltage with the car on right?

How can I test the alt is charging?
Is that ring terminal on the side the positive wire? and it just grounds out through the engine?

Pls try and help. I have to get this running by tomorrow or I have to ride my bicycle to work!

HAILERS

The black/white wire should have 12v when the key is turned to ON. It needs to be installed.

The white/black wire is the wire that goes to the CPU relay in a series four and provides a ground for the idiot light relay.

Frankly it's too hard for me to determine if you have a series four....a series five.....a hodge podge of harnesses or what. But the above paragraph shows the configuration of a series four. Series five wire colors are different.

Digi7ech

iTrader: (1)

It's all series 4 electronics.(S4 TII EFI harness) Just a S5 block and manifolds.

I've rewired the pins to make my voltage and temp gauges work. I then found the similar pins for the NA Alt wires and spliced in 2 wires for the alt. I believe I reversed them when soldering the end plug on for the alt.

With the plug in it constantly ran even with the keys out.

So the White w/ black stripe should be 12v key on. This is part of the charging system or idiot light?

The Black w/ white stripe should be? This should have voltage right(key on)? Then the alt ground it out keeping the idiot lights from going on(which don't come on anyways??wtf?)

I tested for amperage/voltage on the 2 alt tabs in the back and they were fine. I'm getting the alt tested tonight anyways.

Thx. As of right now I'll be riding my bike to work in 90` heat.

HAILERS

https://www.rx7club.com/forum/attach...postid=1389325

Just like this jpg, BLACK/WHITE has 12v on it GOING TO the alternator.

The WHITE/BLACK has no voltage GOING TO THE ALTERNATOR. It acts as a ground for a relay in the CPU, just as shown in the picture. That ground comes from the alternator and goes TO the CPU RELAY. It, the ground, is removed from the relay when the alternator begins to put out.

With the key to ON you probably will see 12v coming from the CPU to the alternator on the WHITE/ BLACK wire, but this is just backveed from the relays coil.

The BLACK/WHITE goes to the top of the plug.

The bike ride will do you good.

The WHITE/BLACK wire comtributes nothing to the output of the alternator.

NEVER ground anything on an alternator. Ain't needed. Your asking for trouble if your looking to ground the alternator. It's bolted to the engine.......which has a big *** ground wire on it at the starter attach bolt.....and that ground wire is attached to the chassis below the left strut tower and also .....at the battery negative post.

Digi7ech

iTrader: (1)

Ok so the Black with white is for idiot light only.

So my question is. By not having this White/black stripe wire plugged into the back, will it cause the alternator from charging?

Pretty much no matter how much I raise the RPM there is no increase. It stays at 11.9-ish volts.

Theres not much that can go wrong in this right?

I never modified the drivers side.

I mean. The alt can't dump it's power any where can it?or is that the problem?
It is eaither charging or not right?

Anyways, Yeah biking is good but not when it's involuntary Good thing I have a Camel backand Cd player. It's like a 20 minute ride to work.
It's a K2 Razorback 4.0. mmm fully suspension

Radial GT

iTrader: (16)

You could also just run one wire from the alt. to the positive on the battery. That is how my GTU is wire because of the microtech, and I'm charging 14.9V constantly. On the back of the Alt there is a two prong connection, you want to splice into the top wire (picture the connection as a T made with two connectors, use the top of the T, ie. the top wire. ) and run that to your positive, presto instant charging. If you have any more charging questions PM me.

HAILERS

**** my question is. By not having this White/black stripe wire plugged into the back, will it cause the alternator from cha****

It's a reference voltage for the voltage regulator. The voltage regulator in the alternator wants/needs to know the state of the battery charge so it can .....regulate the output of the alternator. Your alternators are probably ok.

Next time you have a low output problem, run the engine and look at the voltage right at the alternators output terminal to verify that it's not a bad connection b/t the alternator and the fuse box/battery.

HAILERS

****Pretty much no matter how much I raise the RPM there is no increase. It stays at 11.9-ish volts.****

Oooops. That makes me wonder a bit.

You might want to read this: http://www.vtr.org/maintain/alternator-overview.html

The very last paragraph summary is relevant. I'd ignore the references about the idiot light and the way it woks. Not relevant imho

And, yes, it's excitation voltage for the field.

WAYNE88N/A

If it's just reading battery voltage, then the alt is doing NOTHING, you're reading the batt voltage, not the alt (probably reading it on the upper terminal, right?)

It sounds like you don't have the field excitation wire connected properly (which is the B/W wire in HAILER'S schematic above)...no excitation, no output

If you're using an S4 alt with an S4 N/A harness, that wire will be the top input at the back...any other car or harness combo, I don't know

If you're gonna wire it per Radial GT's post, please protect it with a 15A fuse- we have enough fire hazards under our hoods as it is...

Digi7ech

iTrader: (1)

Well I understand now.

Yes I have been testgint the voltage wjile the car is running on the termianls so I knew it was running on engine only.

I'll rewire the plug tonight and hopefully I will have all the bugs fixed.

I still plan to bike to work It'll be a bitch but fun as long as I have water and music

Still having startup problems too. The thing doesn;t want to kick over by itself. I end up having to tow start it.

I'm guessing the walbro isn;t exactly helping the flooding

Digi7ech

iTrader: (1)

well I switched the wires around and tried to turn the car over. It still won't run so I'm getting a new battery.

The first problem is that since I've now rewired and plugged it in the idiot lights now stay on!! ARGH!

me not happy

HAILERS

If the key is ON, and you have the idiot lights on.......take the small two wire plug off the back of the alternator. Quesiton: did the idiot lights go out when you did that? If so....I'd say the alternator took a dump on you.

Digi7ech

iTrader: (1)

yup they don't come on when the plug is out.

I just swapped alternators and it does the same thing.

So I'm guessing that something is going on with the wiring.

What is the voltage supposed to be on those lines?

Shouldn't the idiot lights go on oif the back plug is out?

Right now it's working opposite.
They go off with the plug in and don't go on when the plug is out.

HAILERS

The WHITE/BLACK wire goes to a relay in the CPU. If the alt is not putting out, that wire puts a ground FROM the alt to the relay and pulls it in which in turn puts 12v from another source on the idiot lights and turns them on.

If the alternator is funcitoning as it should, when it starts to put out voltage, the ground is removed from the WHITE/BLACK wire, which in turn makes the relay in the CPU relax and kills the 12v to the idiot lights.

The BLACK/WHITE wire is the excitation wire for the alternator. It puts 12v into the alternator. The fuse for that 12v comes from the crew compartment. Counting from the bottom of the fuse box, it's the third row from the bottom, second fuse from the left. Pull that fuse and you'll see the 12v disappear from the black/white wire if you have a meter on it and the key to ON.

The alt works just fine without the WHITE/BLACK wire connected. It has nothing to do with the alt working or not.....unless it's on the wrong spot on the alt. It should be on the bottom of the two wire connector on the alt.

I thik I'll get out of the alternator response business after this post. It's gettin old.

HAILERS

The WHITE/BLACK wire goes to a relay in the CPU. If the alt is not putting out, that wire puts a ground FROM the alt to the relay and pulls it in which in turn puts 12v from another source on the idiot lights and turns them on.

If the alternator is funcitoning as it should, when it starts to put out voltage, the ground is removed from the WHITE/BLACK wire, which in turn makes the relay in the CPU relax and kills the 12v to the idiot lights.

The BLACK/WHITE wire is the excitation wire for the alternator. It puts 12v into the alternator. The fuse for that 12v comes from the crew compartment. Counting from the bottom of the fuse box, it's the third row from the bottom, second fuse from the left. Pull that fuse and you'll see the 12v disappear from the black/white wire if you have a meter on it and the key to ON.

The alt works just fine without the WHITE/BLACK wire connected. It has nothing to do with the alt working or not.....unless it's on the wrong spot on the alt. It should be on the bottom of the two wire connector on the alt.

I thik I'll get out of the alternator response business after this post. It's gettin old. Let Icemark do the electrical and go nuts. I'm going to specialize in oil injectors from now on.

Icemark

ah man, you were doing fine... and I didn't have to answer

HAILERS

Mr Ice. See this smiley???

Digi7ech

iTrader: (1)

wait a minute. It's been 4 months since I've driven a Rx7.

With the key in the on position it shoudl have the dummy lights on right?since it's in the on position but not running right??

I still cannot get my car to turn over by starter so I haven't fully tested this then right?

Hmm I'll try this tomorrow and hopefully I will not have to worry about this.(already have a oil leak in the turbo to worry about )

Thx Hailers for the help I know I've been beating this topic like a dead horse but I literally failed Electronic class in high school Altough I have gotten better due to forceful non running FC's

I also don't think my OMP is injecting but I'm going to use some broken OMP lines to test the cc's it puts out.